1. Field
This invention relates to microprocessors. In particular, the invention relates to processor security.
2. General Background
Advances in microprocessor and communication technologies have opened up many opportunities for applications that go beyond the traditional ways of doing business. Electronic commerce (E-commerce) and business-to-business (B2B) transactions are now becoming popular, reaching the global markets at a fast rate. Unfortunately, while modern microprocessor systems provide users convenient and efficient methods of doing business, communicating and transacting, they are also vulnerable for unscrupulous attacks. Examples of these attacks include virus, intrusion, security breach, and tampering, to name a few. Computer security, therefore, is becoming more and more important to protect the integrity of the computer systems and increase the trust of users.
Threats caused by unscrupulous attacks may occur in a number of forms. For instance, an invasive remote-launched attack by hackers may disrupt the normal operation of a system connected to thousands or even millions of users. A virus program may corrupt code and/or data operating on a single-user platform or may propagate itself to other platforms when connected to a network. Although anti-virus programs have been developed to scan, detect and eliminate known viruses, a large performance penalty would be incurred if an anti-virus program is required to examine every file before it can be opened.